3 day emergency pill

3 day pill

3 day emergency pill

This method of emergency contraception is one tablet that contains levonorgestrel. 

The tablet should be taken as soon as possible after unprotected sex, but can be used within 3 days (72 hours).

The 3 day pill is more effective the sooner it is taken.

The tablet works by delaying ovulation - delaying the relase of an egg so that it can't be fertilised.

When in my cycle is emergency contraception effective?

How effective is the 3 day pill as emergency contraception?

The 3 day emergency pill is very good at preventing pregnancy, but 1-3% of users will still become pregnant. This is because the pill cannot prevent ovulation if it has already happened. 

Where can I get the emergency pill?

  • Sexual health clinics
  • GP Surgeries
  • Young peoples clinics e.g. Brook
  • Pharmacies
  • Online

Find an NHS sexual health clinic - contraception is free from the UK National Health Service, but in pharmacies and online you may have to pay.


  • Easy to take - one tablet only
  • Good at preventing pregnancy - 97 to 99% effective
  • Effective up to 3 days after unprotected sex
  • Safe and convenient
  • No need to wait to start or restart hormonal contraception methods
  • No effect on future fertility
  • Available without a prescription
  • Can be obtained 'just in case'


  • May cause some vaginal spotting/bleeding

  • The next period might be on time, or it might come early or late

  • Not as effective as the copper IUD or 5 day emergency pill

  • Does not prevent pregnancy if ovulation has already happened (in the second half of the cycle)

  • Less effective if the BMI is over 26 or weight is over 70kg

How does the 3 day pill work?

Levonorgestrel works by delaying ovulation (egg release). Sperm can be active for five days (or more). If the ovaries release an egg once sperm are no longer active, there will be no pregnancy.

How will I feel?

1 in 10 people experience some side effects after taking the 3 day emergency pill including

  • Nausea
  • Headache
  • Stomach pain
  • Irregular bleeding until the next period, the next period may come earlier or later than expected

There are no serious side effects.

How effective is 3 day emergency contraception?

  • 1-3% of people who take levonorgestrel after unprotected sex will become pregnant
  • The effectiveness will depend upon the timing in the cycle - it can't delay ovulation if it has already happened. The only method that can be effective after ovulation is the Emergency Copper Coil (IUD).
  • It is worth taking the 3 day pill even if you think you have already ovulated, since ovulation can be difficult to predict

See How the body works

Good to know

The 3 day pill (levonorgestrel) is not an abortion pill, and there is no risk that it will harm an existing pregnancy

There is no risk to future fertility.

Emergency contraception can be used repeatedly if necessary:

  • It can be taken again if there is more unprotected sex in the same cycle
  • There is no harm to the body in taking it repeatedly
  • There is a small chance of pregnancy every time though, and a more reliable method is recommended - see What's right for me?

The 3 day pill is free from NHS services (e.g. your GP or Sexual Health Clinic) in the UK, and available to buy without a prescription in pharmacies and online.

You can obtain emergency contraception tablets in advance, to allow you to take it sooner after any unprotected sex.

You do not need to avoid alcohol.

If you are sick within 3 hours of taking the tablet, you will need to take another one.

You can start or restart a hormonal method of contraception straight away.

If you have recently given birth, you can use the 3 day emergency pill from 21 days after birth.

If you are breastfeeding, do not breastfeed for 8 hours after taking levonorgestrel - express the milk and discard it.